The field of the invention relates generally to an electrical machine having a brake, and more specifically, to an axial flux electrical machine that includes an integral braking mechanism.
One of many applications for an electric motor is to operate a hoist or a lift. The electric motor may be configured to rotate a gearbox and/or a pulley system including a drum, a lifting cable, etc., which lifts and lowers a load. In general, the lifting cable is wound onto the drum via operation of the electric motor provided in the hoist or lift, such that an object attached to the cable is lifted. The object may then be placed at a target location by unwinding the lifting cable from the drum by operation of the electric motor, thereby enabling the object to be lowered onto the target location.
In general, electric motors used in hoists or lifts require a brake that is automatically engaged upon deactivation of the electric motor and disengaged upon activation of the electric motor. The brake may function to stop a moving load (dynamic braking) and to hold the load in place (static braking) while it is being positioned at the target location. The brake may also function as a safety device to keep the load from falling should the electric motor lose electrical power. Typically, the brake is an add-on component to the electric motor. As a result, typical electric motor brakes add significant length and weight to the electric motor, thereby increasing the size and weight of the hoist or lift. Furthermore, an add-on motor brake may increase the costs associated with the hoist or lift system.
A common motor used in such hoist and lift systems is a radial flux motor, where the flux extends radially from the axis of rotation. However, a radial flux motor may be large in size and heavy, thereby increasing the size of the hoist and decreasing the hoist-lifting capacity. Another type of motor that may be used in the hoist and lift applications described above is an axial flux motor in which the flux in the air gap extends in a direction parallel to the axis of rotation of the rotor. An axial flux motor may include an integral brake design that may facilitate decreasing the size, weight, and cost of such hoist and lift systems.